A Friendly Tour of Process Memory on Linux

An in-depth exploration of Linux process memory management on x86-64, covering virtual memory areas (VMAs), page tables, and address translation. Explains lazy allocation through page faults, copy-on-write mechanics in fork() and MAP_PRIVATE, and permission changes via mprotect. Details transparent huge pages (THP), dirty tracking with userfaultfd and PAGEMAP_SCAN, TLB invalidation costs, and Page Table Isolation (PTI) as Meltdown mitigation. Includes practical guidance on using /proc interfaces like maps, smaps, and pagemap to inspect memory state, plus common pitfalls with mmap, file mappings, and memory protection.